Fluid engine



Nov. 30, 1954 F. E. GRIFFITHS FLUID ENGINE 5 Sheets-Sheet 1 Filed Dec. 13, 1950 F rank/in E. Griff/Ills INVENTOR.

Nov. 30, 1954 Filed Dec. 13, 1950 F. E. GRIFFITHS FLUID ENGINE 3 Sheets-Sheet 2 Frank/in 1 Griff/Ms INVEN TOR.

Nov. 30, 1954 F. E. GRIFFITHS FLUID ENGINE 5 Sheets-Sheet 3 Filed Dec. 13, 1950 I Frank/m E Griff/Ms INVENTOR.

a of the: housing, housing. and then sidewaysto the: other-side oftheihouse'inithe direction of the ted States Patent ':This' invention relates; to.1improvemeuts. in fluictvengines,

.zmotorssand .pumps ioftthe pistonsitype.

.An object of this inventiontis to provide taxdevice vwhich with. minor changes .may .bevusednlasa motor, .pmnp or other analogous tmachines', -:the zdevice shaving iforzitsmain purpose IO'PIOVldGLa new assemblywhich toperates .onca. new principle of .movement, there being awcasing or housing with.arpistonltherein the piston having sliding vanes which .constitutethe 'side walls of expansion chambers, the expansion chambers being in-a series on the outside surface of the piston. and in a series 1 defined by the inside being a means provided totconstrain the movement of surface of the piston and there the .piston so that it does not rotate iuzvanexactcircular spatlrof movement about the shaft aswan'axis and does :not'rnove in the standard pathrof movement aswin' a :sliding .vane

type of pump but 'rathermoves' from an initial starting, position. arbitrarilyxconsidered at the: top downwardly and: toward: oneaside .ofcthe ing: and then upwardly to; the initialistartingtpositionr .Ancillary objects andfeatures of. importancewillbe- 'come apparent in following the description of the illustrated. form of the invention.

.Inzthe drawings:

7 Figure 1 is an exploded. perspective view'ofs'someof the parts of the device.

.Figure 2 is a sectional view of the assembled device andtaken substantially on the line 22 of Figure-B and arrows;

Figure 3 is a transverse sectional view taken onthe line 3-3 of Figure 2 and in the direction of the arrows;

Figure 4 is a sectional view somewhat similar to that of Figure 3 but showing thepistonin a. second position; Figure 5 is a sectional view similar to Figure 4 but showing the piston in a third position;

Figureu6 is a. sectional view-taken on the line"66 of FigureZ and in. the direction of the arrows; and

:Figure 7 is a fragmentary sectionaliview ofthedevice,

. showing a modification.

.The illustrated embodimentof the invention includes a housing 10 which is made of a first end wall 12, a second end wall 14 and a side wall 16. The end wall 14 is bolted or otherwise rigidly secured to the side wall 16, and the side wall is mounted on a base 18.

Spindles 20, 22, and 24 are circumferentially spaced from each other and extend from the inside surface of the wall 12. Rollers 26, constituting guides, are disposed on the spindles, 20, 22 and 24 and are arranged to be located in the circumferentially spaced recesses 28, 30 and 32 formed in the end wall 34 of the piston 36.

The piston is located within the housing 10 and is of special construction. There is a bore 38 formed in the piston 36 and a counterbore 40 in communication therewith. This counterbore opens toward the end wall 14 of the housing, and the bore 38 accommodates the eccentric 42 which is fixed to the shaft 44. This shaft is mounted axially within the housing 10 and has one end passed through standard anti-friction bearings 43, which are disposed in an opening in the end wall 12 of the housing. The opposite end of the shaft has a threaded axial opening 46 to accommodate a fastening element, as a bolt 48 which is employed for the purpose of holding the valve member 50 fixed to the shaft for rotation therewith. This valve member is keyed as at 52 to insure that there will be no relative movement between the valve member and the shaft 44.

2,695,597 Patented Nov. 30, 1954 @Theepiston? 36 is provided: with; agplurality of; s1otsr518,

:60randi.62which are arranged radially therein andwhich :,open-outwardlytthrough-tthesside wall of .theupiston. Dividers; 64, :66.and 6s .aretslottably: disposedin'; the slots :.58,;-60;:andl 62 and :have their outerxends in contact with athednner-surface; oftthe side wall 14'of the.;housing;:10. :The dividersmwithwthe outsidessurface of. the side wall of the piston and .theinside surface of. the side wallH16 :of .theihousing constitute separate expansionqchambers forathe fluid underzpressuretwhich isnintroducecl intouthe main chamber of :the pump.

Internal expansion chambers are: arranged between; the -sideszrof..the dividers, thezinside; surface of the sidewall -.of' the piston 1 andathevoutside surface: of an extension element =70 fixed ..to: or...integrally-;counected-withathe "inside surface of: the endwvalli14.

:Ihisa extension .elementzhassrarrecess f72zformed: therein in order to accommodatethe;bearing;74r .Thelbearingris wsoz designedpas: to withstand the: loads: and. thrusts of, the shaft. 44: inasmucha ascthe. enlargement 76: ofttheishaftn44 'is disposed: 0111116. inner. race. of;;the;bearing .74.

In orderto-helpsupport the loadrofthe shaft 441116 i'bearing: .43 is provided in .the l bearing ,cap "180 which is ..formed. in the material. of the end wall 12. .A, standard oilseal 82 is used inthe openingqof the bearingcap? to serve its usual function.

a Means for: introducing. fluid, as air, under pressure; into the (inner. expansion chambers anduthe 'outeruexpansion -chambers,.are provided. "Preferable means consist-of an :air. inlet member LS4 which. is. fixed. to' the air: inlet: assembly capt86. and which opens-into .antair conducting chan- -nela88. Thisichannel. is: formed in 141116 valvev member; 80 sand." is spaced between: the. outer. flange r'9tlwaud. the hub 92sof1ithe valvermember. 50. 1A first airinlet openingw94 is formed in the valve memberx50 and aisecond opening "96 formed linxthe va1ve:member 150,; the opening: 94 being 2 in a; circle of larger. diameter thantthetcircle. containing the opening 96. Accordingly. the opening 94is arranged ..to1cornmunicatewith\the: air conducting channel 98wliile -.lthe opening 96 isJarranged tocommunicat-ei with theair tconductingchannel. 100. The: channel 98.. is L divided: into z threeusectionssbylmeans of thepartitions 102, and the .channel 100. is divided" into three *sections 'by 1 means of the;partitions;104. Whenrthe cap-86is boltedtoxthe .end wall 14 the valve member 50 is disposed" between the :capi-86 xan'dt theschanuelst98: and 100 in; order to. control the admission ofzair into. theasections of thechannelsv98 and 100. :Inasmuch assthe valve member-50; is'fixe'd .to thepower output shaft 44'the admission ofiair under vpressure is .controlleduas to l the selection of expansion cchambersiin. accordance with the positionof therpiston 'iagdrthe' position of. the shaft 44 in the casing or housing I];

There/are twozsets provided in: the end wa'll l l. One .:set .opensintoithe: inner expansion chambers .andzthe air conducting channel-100, :i-wliiletthe otheruset of channels open into the outer expansion chambers and the air conducting channel 98.

In this respect attention is invited to Figure 2 where the passage is shown as being in communication with the closed expansion chamber and the channel 112 of the other set of passages is illustrated as being in communication with the open outer expansion chamber.

Inwardly opening channels 114 are provided in the side wall 16 of the housing 10 and form continuations of the passages 112 so that the fluid under pressure is introduced into the expansion chamber along the same axially of the piston and shaft 44.

The end wall 12 is provided with three curved discharge ports 116, 118 and 120. The end wall 14 is provided with three discharge ports 122.

The operation of the device is as follows:

Air under considerable pressure is introduced into the expansion chambersf Any standard means of putting the air under pressure may be used, as the pump schematically shown in Figure 1.

When the air pressure is applied at the inlet member 84, the channel 88 receives this air under pressure. The aperture 84 being in communication with the passage 112 conducts the fluid under pressure into one action chamher for example the chamber 120 (Figure 3).

cordingly since there is rotation of the shaft 44, the valve member 50 is caused to rotate thereby moving the valve member 50 to such position that air under pressure from the channel 100 passes through the passage 110 and into one of the inner expansion chambers, for example the expansion chamber 122. The inner expansion chamber and the single outer expansion chamber which are being used at this time cooperate to produce a single movement of the piston. The result of this movement may be observed by comparing the location of the piston with respect to the housing in Figure 3 and the location of the piston with respect to the housing in Figure 4.

With the structure described previously pressure applied in the chambers 120 and 122 would in all probability cause rotation of the piston 36 instead of substantially linear displacement as disclosed in Figures 3-5. Therefore there is a means provided for the purpose of constraining the movement of the piston 36.

. Noting the piston 36 of Figure 1 which is separate from the general assembly and which is inverted, the re cesses 28, 30 and 32 are illustrated as being in the side walls 34 of the piston. This piston being fitted on the shaft 44 through the medium of the eccentric and its bore 38, causes the recesses to encompass the guides 26. Therefore, when force is applied to the piston it can move only in a prescribed travel inasmuch as the guides prevent true circular movement of the piston 36 and will not allow true reciprocatory movement of the piston. However when the piston is moved it is displaced laterally causing the rollers to assume positions in the recesses as disclosed in Figures 3-5 inclusive. being displaced laterally caused the guides 26 to assume difierent position on the inside circular walls of the recesses 28, 30 and 32. In other words, they ride upon the surfaces of the recesses.

When the piston 36 has moved down and to the side as disclosed in Figure 4 the expansion chamber 120 has been opened to the full extent and the same is true of the chamber 122. Slightly prior to this time the valve 50 has been moved by rotation of the shaft 44 to such position that air under pressure has started to enter the expansion chamber 126 and the inner expansion chamber 128. There is a considerable degree of overlap in the valve assembly, the overlap being up to sixty degrees of shaft rotation.

As the piston starts to move from the position shown Q in Figure 4 to the position of Figure 5, the exhaust port 116 for the chamber 120 is opened inasmuch as the outer wall of the piston moves from its covering position, and the corresponding outlet port 122 in the end wall 14 is opened for the same reason. bers are exhausted and meanwhile the second impulse has begun because of the introduction of fluid under pressure through the appropriate passages 110 and 112.

The above cycle continues until such time that the air supply from the pump P is stopped.

The piston 36 0 Accordingly these cham- By virtue of the described structure and its operation the piston 36 does not move rotatively in the sense that the shaft 44 rotates. Rather, it is shifted laterally within the housing 10 by the expansion of the motive fluid.

For balance purposes more than one eccentric 42 may be used with a corresponding change in design of the piston to accommodate the multiple eccentric on the shaft Attention is now invited to Figure 7 wherein a slight modification is illustrated. Instead of employing a bushing, as at 39 in Figure 2, roller bearings 41 may be used to reduce friction when the piston 36 and eccentric move with respect to each other, by being located between the piston 36 and eccentric 42 and in the bore 38.

Having described theinvention, what is claimed as new is:

1. In a fluid motor, a cylindrical casing, a shaft disposed axially within said casing and mounted for rotation therein, an eccentric fixed to said shaft, a piston disposed within said casing, said piston having an axial bore receiving said eccentric, said piston also having an enlarged counterbore in one end, end walls closing the ends of said casing, an extension on one of said end walls projecting into said counterbore, said extension being of smaller diameter than the counterbore by an amount equal to the eccentricity of said eccentric and being disposed in concentric relation to said shaft whereby the points of engagement between said extension and said piston on the one hand and between said casing and said piston on the other hand are in diametrically opposed relation with respect to said piston, said piston having a plurality of equally and circumferentially spaced slots, a plurality of dividers slidably carried within said slots and having inner and outer edges continuously engaging said extension and the inner surface of said casing respectively, whereby inner expansion chambers are provided within said counterbore and outer expansion chambers are provided between said casing and said piston, guide means on one of said end walls contacting said piston and constraining movement of the center of the latter to revolution about the axis of said shaft, and means connected with said shaft and constituting a valve for controlling the simultaneous admission of fluid into pairs of said expansion chambers, said pairs comprising an inner and an outer expansion chamber.

2. The combination of claim 1 wherein at least three dividers are provided and said valve means includes mech anism for overlapping the admission of working fluid in successive inner and outer chambers.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 448,607 Gollings Mar. 17, 1891 456,351 Adams July 21, 1891 1,594,035 Bailey July 27, 1926 1,824,081 Heller Sept. 22, 1931 1,906,142 Ekelof Apr. 25, 1933 

